There are two questions that arise out of the furore over James Watson's
comments. Is race a valid scientific category? And should scientists refrain,
for moral reasons, from speculating about racial differences?
There are clearly genetic differences between human populations. North Europeans
are more likely to suffer from cystic fibrosis. Tay Sachs disease particularly
affects Ashkenazi Jews. Beta blockers seem less effective on African Americans.
Yet race is rarely a good guide to the distribution of genes. We all know,
for instance, that sickle cell anaemia is a black disease. Except that it
isn't. It's a disease of populations originating from areas with high incidence
of malaria. Some are black, some are not. The sickle cell gene is found in
parts of equatorial Africa, southern Europe, the Middle East and central India.
Most people, however, know that African Americas suffer disproportionately
from the trait. And they automatically assume that what applies to black Americans
also applies to all blacks and only to blacks.
What the sickle cell story shows is that genes do not respect the socially
defined boundaries of human groups. The distribution of genes rarely matches
the distribution of populations. What we call races are often irrelevant to
the study of gene distributions. Genetic variation among Africans is often
greater than that between blacks and whites. Sub-Saharan Africans and Australian
Aborigines are both labelled 'black'. Yet, there are few populations that
are genetically more distinct.
If the relationship between race and disease is fraught, that between race
and intelligence is even more so. Intelligence has never been properly defined,
no one knows what IQ tests actually measure, and we have yet to identify the
genes that underlie the myriad of attributes that collectively give rise to
intelligence. Given all this, making simplistic claims about the racial distribution
of intelligence smacks more of alchemy than of science.
In my opinion, James Watson got his facts in a double helix. But did he have
the right to speculate about race and intelligence in the first place? I believe
he did. When the Science Museum cancelled Watson's lecture last week, it claimed
that 'he had gone beyond the point of acceptable debate'. Nonsense. It is
as legitimate for Watson to express his opinion as it is for me to express
mine, even if that opinion is factually wrong, morally suspect and politically
offensive. That is the essence of scientific debate.